Are you using both web2.0 portal (e.g. Netvibes or PageFlake) , web-based aggregator (e.g. Bloglines) as well as desktop rss reader in different environments like me? If so, have you suffered from the pain about updating a new RSS at multiple sites. The following is my experience:

I see an interesting site with RSS feed, I first add it in my bloglines feed list (This is easily finished by firefox livelines plug-in). However, if I don't update the opml files of the other sites previously imported from bloglines, I cannot read this new interesting site in other environments. I have to do this manually and it is very boring!

Today, I come out a new idea about this issue called - RSS of RSS. RSS is used to synchronize the content of individual distributed site for central access. By extending the scope of RSS, this can be applied to any content that are to be accessable elsewhere. For opml files, the solution of creating a RSS feed for my feed list and using RSS instead of importing OPML will easy our life! We only need to update a centralized location and other environment will automatic update!